The 10.1.1.1 subnet is now running out of ip addresses and now I am thinking how can I increase the ip address on this subnet. We already have used almost all IP address and need more ip address in next two days. Please provide some expertise on this.

This is a bigger project than you might think. Make sure you have clearly
defined the static IP address range which hopefully is continuous. Let's
assume your is 10.1.1.1-50. and your DHCP range is 10.1.1.51-254 Your new
DHCP range will be 10.1.0.1-10.1.1.254 with an exclusion your original
static range.
All static devices, servers, printers, routers, will need to have their IP
info edited manually. And you should be prepared to refresh the leases on
all DHCP hosts. You got lucky because the DHCP server will hand leases out
starting with 10.1.0.1 and go up so you won't have duplicate addresses on
the network while the HOSTS run on the old lease. When I went through this
I sent an email out asking everyone to shut their computer down that night
if they don't normally.
This is a link to some info about setting up DHCP on Server 2003 if you are
a real novice.

You are using a class "A" IP address (10.X.X.X), this IP address has default subnet mask 255.0.0.0, you are using a Class "C" subnet mask (255.255.255.0) with a class "A" IP adddress, It means, you're using an incorrect subnet mask. Use 255.0.0.0 subnet mask and solve your problem. After this, i recommend you, read about subnet masks then you can understand about it. I hope you solve your problem.

Hi, generally speaking, use supernet with a mask of 255.255.254.0 (prefix 23) would solve your problem, but by doing so, it would also require a lot of extra work. for example, the mask on any infrastructure server system, the IP address configuration on router/routers internal port, the NAT configuration on a router, the static route configuration on your router or routers. but the potential problem is the broadcast storm on such kind a network. You should consider using vlan to structure your intranet network, with a tiny adjustment on your router/routers.

I had the same problem and I changed the default subnet mask 255.0.0.0 and it works fine. Also and depending your infrastructure (Static IP address, reserved IP ranges, specially router and maybe you have Vlan-Inter-routing ) you configuration should follow the new settings. But according to me, changing the subnet mask to 255.0.0.0 will resolve the problem.
If you find out the solution please kindly share.
Good luck

I had the same problem and I changed the default subnet mask 255.0.0.0 and it works fine. Also and depending your infrastructure (Static IP address, reserved IP ranges, specially router and maybe you have Vlan-Inter-routing ) you configuration should follow the new settings. But according to me, changing the subnet mask to 255.0.0.0 will resolve the problem.
If you find out the solution please kindly share.
Good luck